The present invention broadly relates to continuous casting and, more specifically, pertains to a new and improved method and apparatus for regulating the flow of an electrically conductive liquid, especially a bath of molten metal in continuous casting.
Generally speaking, the apparatus of the present invention comprises a pouring tube having a conduit, the conduit having a central region, and an electromagnetic coil having an electromagnetically effective length arranged concentrically about the pouring tube.
In continuous casting, the flow of metal from one vessel to another, for instance from a ladle to a tundish or from a tundish to a continuous casting mold, is regulated by stoppers or sliders or gates. The various disadvantages of these regulating members as well as the various malfunctions possibly arising during casting operation are largely known. A few examples are the so-called leaky or running stopper, the solidification of flow sections, the often insufficient regulability, the wear of mechanically moved components, the necessity of a hydraulical actuating or displacement mechanism, et cetera.
It has therefore been attempted in continuous casting according to the prior art to restrict or constrict the cross-section of metal flowing through the pouring tube by means of electromagnetic forces generated by coils arranged concentrically about the pouring tube. However, in this type of electromagnetic influence on the casting or pouring stream, the effect exerted is insufficient. In particular, it is not possible to completely stop the metal flow, since the metal flow to be influenced, for physical reasons, can indeed be restricted to a certain extent but not fully constricted.